1. Field of the Disclosure
The present disclosure relates to a light emitting diode (LED) lamp controller, and more specifically to a LED lamp controller with delayed startup under fault conditions.
2. Description of the Related Arts
A controller circuit for a LED lamp must detect and respond appropriately to many potential fault conditions. Generally, when a fault is detected, the controller circuit stops driving its output pins and enters a shutdown state to prevent any further damage from occurring. After some amount of time, the controller restarts and the LED lamp will be powered up if the fault condition has been removed. During each restart, the controller enters a configuration state during which the internal parameters affecting operation of the controller are configured. Once the configuration state is completed, the controller enters a regulation state and begins to regulate current to the LEDs of the LED lamp.
If the fault condition is still present, the controller will shut down again, and the power cycle will be repeated. A high amount of power consumption in the LED lamp can occur during the time that the controller is in the configuration state due to the way in which the controller is driving the circuitry of the LED lamp. Repeated power cycles cause thermal stress on circuitry in the LED lamp if the amount of time spent in the configuration states is too long.
To reduce the thermal stress during repeating power cycles, once a fault is detected, conventional LED lamp drivers prevent the LED lamp driver from completing the start up process for a fixed number of subsequent power cycles. However, conventional LED lamp controllers are fairly simplistic and use a one-size fits all approach that treats all fault conditions in the same manner, regardless of the severity of the fault. In addition, fault detection circuits in conventional LED controllers are limited in the types of faults that they can detect.